Remote-sensing image. The item is a remote-sensing image, defined as an image produced by a recording device that is not in physical or intimate contact with the object under study. This may be a map or other image that is obtained through various remote-sensing devices such as cameras, computers, lasers, radio frequency receivers, radar systems, sonar, seismographs, gravimeters, magnetometers, and scintillation counters. When the image has cartographic or bibliographic information added, it is referred to as a remote-sensing map.

Unspecified. The specific material designation of the remote-sensing image is not specified.

Surface. The remote-sensing image was made from a device located on the surface of a body, usually a planet or moon.

Airborne. The remote-sensing image was made from a device above the surface of a body, generally in the atmosphere, an aircraft, balloon, or some other airborne device.

Spaceborne. The remote-sensing image was made from a device in space. Spaceborne sensors are those located outside the primary layers of an atmosphere (usually in orbit) and beyond.

Not applicable. The altitude of the remote sensor is no applicable to the image (e.g., sonar, etc.).

Unknown. The altitude of the remote sensor from which the image was made is not known.

Other. A position of the remote sensor for which none of the other codes is appropriate.

Low oblique. The remote-sensing device is closer to parallel with the surface being imaged than perpendicular. At a low oblique angle, the horizon is not shown in the image.

High oblique. The remote-sensing device is closer to perpendicular than not. At a high oblique angle, an apparent horizon line appears in the image.

Vertical. The angle of the remote-sensing device is vertical to the surface being imaged. A vertical angle is the most frequent angle for aerial photographs; the remote sensor is directly above the surface being imaged, with the line of sight of the sensor perpendicular to the surface.

Not applicable. The angle of the remote-sensing device is not applicable, generally, because the attitude does not affect the image.

Unknown. The angle of the remote-sensing device is not known.

0-09%

10-19%

20-29%

30-39%

40-49%

50-59%

60-69%

70-79%

80-89%

90-100%

Not applicable. The amount of cloud cover is not applicable to the image.

Unknown. The amount of cloud cover is not known.

Balloon. The base for the remote-sensing device was a balloon or similar lighter-than-air platform.

Aircraft—low altitude. The base for the remote-sensing device was a dynamic lift aircraft designed for low altitude flight (below 29,500 feet (8,962 m)).

Aircraft—medium altitude. The base for the remote-sensing device was a dynamic lift aircraft designed for medium altitude flight (between 29,500 feet (8,962 m) and 49,000 feet (14,810 m)).

Aircraft—high altitude. The base for the remote-sensing device was a dynamic lift aircraft designed for high altitude flight (above 49,000 feet (14,810 m)).

Manned spacecraft. The base for the remote-sensing device was a manned spacecraft.

Unmanned spacecraft. The base for the remote-sensing device was an unmanned spacecraft.

Land-based remote-sensing device. The base for the remote-sensing device was a land-based platform type.

Water surface-based remote-sensing device. The base for the remote-sensing device was designed to remain on the surface of a body of water (e.g., a ship or floating platform).

Submersible remote-sensing device. The base for the remote-sensing device was designed to be submerged beneath the surface of a body of water (e.g., a submersible vessel or platform).

Not applicable. A platform construction type for the remote-sensing device is not applicable.

Unknown. The construction type of the platform from which the remote-sensing image was made is not known.

Other. A construction type of the platform from which the remote-sensing image was made for which none of the other codes is appropriate.

Meteorological. The primary use for the platform is to make remote-sensing images of meteorological events and conditions.

Surface observing. The primary use for the platform is to make remote-sensing images of the surface of a planet, moon, etc. (including the Earth).

Space observing. The primary use for the platform is to make remote-sensing images of space.

Mixed uses. The platform from which remote-sensing images can be made is designed for a variety of uses (i.e., uses covered by two or more of the other codes).

Not applicable. The identification of platform use category is not applicable.

Unknown. The platform use category is not known.

Other. A platform use category for which none of the other codes is appropriate.

Active. The remote sensor measures the strength of the reflections of its transmissions sent to a remote target.

Passive. The remote sensor measures the strength of transmissions (e.g., radiation) emitted by a remote target without stimulation by the sensor.

Unknown. The involvement of the remote-sensing device in the creation of the transmission it measured is not known.

Other. A recording mode of the remote-sensing device for which none of the other codes is appropriate.

Visible light. That part of the electromagnetic spectrum to which the human eye is sensitive, between about 0.4 and 0.7 micrometers.

Near infrared. Electromagnetic radiation with wavelengths from just longer than the visible, about 0.7 micrometers, to about 1.4 micrometers. In the near-infrared region, surface chemical composition, vegetation cover, and biological properties of surface matter can be measured using energy naturally reflected or radiated from the terrain.

Middle infrared. Electromagnetic radiation between the shortwave infrared and the thermal infrared, about 3.0 to 8.0 micrometers. In the middle-infrared region, geological formations can be detected due to the absorption properties related to the structure of silicates, using both reflected sunlight and earth-emitted radiation. It is useful for snow-ice discrimination; forest fire detection; plant water content; distinguishing clouds, snow, and ice; and mapping geologic formations and soil boundaries.

Far infrared. Electromagnetic radiation, longer than the thermal infrared, with wavelengths between about 15 and 1000 micrometers. In the far-infrared region, emissions from the Earth's atmosphere and surface offer information about atmospheric and surface temperatures and water vapor and other trace constituents in the atmosphere.

Thermal infrared. Electromagnetic radiation with wavelengths between about 8.0 and 15 micrometers. This region of the electromagnetic spectrum is dominated completely by radiation emitted by the earth and helps to account for the effects of atmospheric absorption, scattering, and emission. It is useful for crop stress detection, heat intensity, insecticide applications, thermal pollution, geothermal mapping, and water surface temperature measurements.

Shortwave infrared (SWIR). Electromagnetic radiation between the near infrared and the middle infrared, about 1.4 to 3.0 micrometers. Shortwave infrared may be useful for mineral exploration, urban features such as roofing and construction materials, vegetation, petroleum (e.g. an oil spill), and a variety of other man-made chemical compounds. Snow and ice display distinctive variations in some SWIR bands. SWIR-based imaging can penetrate some types of smoke, such as from forest fires.

Reflective infrared. Electromagnetic energy of wavelengths from about 0.7 to 3 micrometers that consists primarily of reflected solar radiation. Reflective infrared is useful for the study of vegetation and identification of types of rock and soil.

Combinations. More than one infrared data type is applicable to the remote-sensing image.

Other infrared data. An infrared data type, representing electromagnetic radiation with wavelengths between about 0.7 and 1000 micrometers, for the remote-sensing image for which none of the other codes is appropriate.

Side-looking airborne radar (SLAR). An airborne side scanning system for acquiring real-aperture radar images. SLAR is an all-weather, day/night remote sensor that is particularly effective in imaging large areas of terrain.

Synthetic aperture radar (SAR)–single frequency. A Synthetic aperture radar (SAR) system that transmits pulses in one frequency or wavelength.

SAR–multi-frequency (multichannel). A Synthetic aperture radar (SAR) broadband system that transmits pulses in a range of frequencies and wavelengths.

SAR–like polarization. A Synthetic aperture radar (SAR) designed to both transmit and receive only horizontal polarized microwave signals or only vertical polarized microwave signals.

SAR–cross polarization. A Synthetic aperture radar (SAR) capable of simultaneously and coherently acquiring several independent complex polarization measurements for every pixel in the image.

Polarmetric SAR. A Synthetic aperture radar (SAR) that permits measurement of the full polarization signature of every resolution element.

Passive microwave mapping. Remote sensing using radiation in the 1 mm to 1 m range emitted naturally by all materials above absolute zero.

Other microwave data. A microwave data type, representing electromagnetic radiation with wavelengths between about 1000 micrometers and 1 m, for the remote-sensing image for which none of the other codes is appropriate.

Far ultraviolet. The far-ultraviolet region extends from 0.122 to 0.2 micrometers, approximately from the beginning of strong oxygen absorption to about the limit of availability of rugged window materials, the lithium fluoride transmission limit.

Middle ultraviolet. The middle-ultraviolet region extends from 0.2 to 0.3 micrometers, approximately the region between the solar short wavelength limit at ground level and the onset of strong molecular oxygen absorption. Most solar radiation in this range is absorbed in the atmosphere by ozone.

Near ultraviolet. The near-ultraviolet region extends from 0.3 to 0.4 micrometers, from the short wavelength limit of human vision to about the short wavelength limit of the solar ultraviolet that reaches the surface of the earth. Near ultraviolet may be used in atmospheric observations.

Ultraviolet combinations. More than one ultraviolet data type is applicable to the remote-sensing image.

Other ultraviolet data. An ultraviolet data type, representing electromagnetic radiation with wavelengths between about 0.01 and 0.4 micrometers, for the remote-sensing image for which none of the other codes is appropriate.

Multi-spectral, multidata. The acquisition of remote-sensing images of the same scene in various wavelength bands simultaneously. Multi-spectral remote imaging can be used to distinguish between different types of environments (for example, urban vs. agricultural groundcover).

Multi-temporal. The acquisition of remote-sensing images of the same scene observed through time.

Combination of various data types. More than one data type is applicable to the remote-sensing image.

Sonar--water depth. The acoustical data type for the remote-sensing image for water depth is sonar. This code is also used for echo-sounding images.

Sonar--bottom topography images, sidescan. The acoustical data type for the remote-sensing image is sidescan imaging. Sidescan imaging includes both near-surface and near-bottom sensing data.

Sonar--bottom topography, near-surface. The acoustical data type for the remote-sensing image is near-surface.

Sonar--bottom topography, near-bottom. The acoustical data type for the remote-sensing image is near-bottom (i.e., taken from 10-150 m (33-494 feet) from the bottom).

Seismic surveys. The acoustical data type for the remote-sensing image that measures waves of elastic energy, especially from earthquakes, in reference to a particular area of the Earth's surface to evaluate the subsurface.

Other acoustical data. An acoustical data type for the remote-sensing image for which none of the other codes is appropriate.

Gravity anomalies (general). Remote-sensing data that correct generally for differences between the actual value of gravity measured at a location and the value predicted by a particular Earth model.

Free-air. Remote-sensing data that correct for the change in the gravitational field with height above sea level, assuming there is only air between the measurement station and sea level.

Bouger. Remote-sensing data that correct for variations in gravitational attraction at the point of measurement due to solid earth masses in the crust, or deeper, owing to different rock types and rock densities.

Isostatic. Remote-sensing data that correct for variations in the density or thickness of the Earth's crust.

Magnetic field. Remote-sensing data that measure magnetic field variations including inclination, declination, total intensity, and horizontal and vertical intensity vectors.

Radiometric surveys. A radiometric survey measures the spatial distribution of three radioactive elements (potassium, thorium, and uranium) in the top 30-45 cm of the earth’s crust by detecting the gamma rays produced during the natural radioactive decay of these elements.

Not applicable. A data type is not applicable to the remote-sensing image being described.

Unknown. The data type for the remote-sensing image is not known.

Other. A data type for the remote-sensing image for which none of the other codes is appropriate (e.g., x-rays).